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3 years ago

Math help please !!!!!!!

Mathematics

2 answers:

Nata [24]3 years ago

8 0

a truck can travel 160 miles in the same time that it takes a car to travel 200 miles. If the truck's rate is 10 miles per hour slower than the car's find the average rate for each.

the rate of the car is miles per hour

professor190 [17]3 years ago

3 0

I think it is B. You can draw a horizontal line and it will hit multiple spots so it is not one-to-one

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If F(x)=9x which of the following is the inverse of F(x)

user100 [1]

Answer:

Inverse of F(x)=9x = 1/9x

Step-by-step explanation:

If F(x)=9x

which of the following is the inverse of F(x)

When talking about inverse of a function, we are talking about reversal. Therefore, an inverse function is the inverse of another function. In order to get the inverse of a particular function, we reverse the denominator to become the numerator and the numerator to become the denominator.

So for the function,

F(x)=9x, the numerator is 9x and the denominator is 1

Reversing the numerator and denominator, .

Inverse of F(x)=9x = 1/9x

8 0

3 years ago

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Please help. I just need to get this done lol.

Mice21 [21]

Answer:

1/16

Step-by-step explanation:

6 0

3 years ago

Please help, this is a chapter on Derivatives.

horsena [70]

Answer:

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

In a particular faculty 60% of students are men and 40% are women. In a random sample of 50 students what is the probability tha

zimovet [89]

Answer:

a) The expected value is given by:

$E(X) = np = 50*0.4 = 20$

and the variance is given by:

$Var(X) =np(1-p) = 50*0.4*(1-0.4) = 12$

b) $P(X>25)= 1-P(X\leq 25)$

And we can find this probability with the following Excel code:

=1-BINOM.DIST(25,50,0.4,TRUE)

And we got:

$P(X>25)= 1-P(X\leq 25)=0.0573$

c) 1) Random sample (assumed)

2) np= 50*0.4= 20 >10

n(1-p) =50*0.6= 30>10

3) Independence (assumed)

Since the 3 conditions are satisfied we can use the normal approximation:

$X \sim N(\mu = 20 , \sigma= 3.464)$

d) $P(X>25) = 1-P(Z< \frac{25-20}{3.464}) = 1-P(z$

e) $P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)$

$P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)= 1-P(Z$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=50, p=0.4)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

Part a

The expected value is given by:

$E(X) = np = 50*0.4 = 20$

and the variance is given by:

$Var(X) =np(1-p) = 50*0.4*(1-0.4) = 12$

Part b

For this case we want to find this probability:

$P(X>25)= 1-P(X\leq 25)$

And we can find this probability with the following Excel code:

=1-BINOM.DIST(25,50,0.4,TRUE)

And we got:

$P(X>25)= 1-P(X\leq 25)=0.0573$

Part c

1) Random sample (assumed)

2) np= 50*0.4= 20 >10

n(1-p) =50*0.6= 30>10

3) Independence (assumed)

Since the 3 conditions are satisfied we can use the normal approximation:

$X \sim N(\mu = 20 , \sigma= 3.464)$

Part d

We want this probability:

$P(X>25) = 1-P(Z< \frac{25-20}{3.464}) = 1-P(z$

Part e

For this case we use the continuity correction and we have this:

$P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)$

$P(X>25)= P(X>25.5) = 1-P(X \leq 25.5)= 1-P(Z$

4 0

3 years ago

Let A and B be sets with cardinal numbers , n(A) = a and n(B) = b respectively . Decide whether the statement is true or false.

olya-2409 [2.1K]

Answer:

True

Step-by-step explanation:

$A\cup B=A\cup(A-B)\\\\A\ and\ A-B\ are\ disjoint\ that\ means\ there\ is\ no\ common\ element\ in\ these\ two.\\\\n(A\cup B)=n(B\cup(A-B))\\\\n(A\cup B)=n(B)+n(A-B)\ \ \ \ \ \ \ as\ for\ disjoint\ set\ P,Q\ n(P\cup Q)=n(P)+n(Q)\\\\(n(P-Q)=n(P)-n(P\cap Q))\\\\n(AUB)=n(B)+n(A-B)\\\\n(AUB)=n(B)+n(A)-n(A\cap B)\\\\n(AUB)=n(A)+n(B)-n(A\cap B)\\\\Hence\ given\ statement\ is\ true$

4 0

3 years ago